Telephone-exchange system.



A. E. LUNDELL. TELEPHONE EXCHANGE SYSTEM- APPLICATION FILED SEPT-Z2. I916- Patented Aug. 21, 1917. 2 $flEETS SHEET I //1 venfor:

/4/b e/7. L unde WM y AW A. E. LUNDELL. TELEPHONE EXCHANGE SYSTEM. PLlCATlON FILED SEPT. 22, 1916.

Patented Aug. 2 1, 1917 2 $HEETS$HEET 2.

I hymen/arm Awe/7'5 La/ deM l l NITED STATES PATENT OFFICE ALBEN E. LUNDELL, OF NEW YORK, N. Y., ASSIGNOR TO WESTERN ELECTRIC COMPANY,

INCORPORATED, OF NEW YORK, N. Y.,- A CORPORATION OF NEW YORK.

TELEPHONE-EXCHANGE SYSTEM.

Specification of Letters Patent. Patented Aug. 21, 1917.

Application filed September 22, 1916. Serial No. 121,566.

. To all whom it may concern.-

According to one feature of the invention,

' means are provided to cause a switch to hunt over a row of terminals in both its forward and return movements.

According to another feature of the invention a plurality of line-finder switches, each in a different position over its bank of terminals, are adapted to take up the search for a calling line simultaneously. When one is successful in finding the line which has initiated a call, all are arrested in the positionwhich they have at that time reached, and remain in such a position until the initiation of a new call. At that time all of those line-finders which are still idle start on a new search. Each one of these switches is provided with means to cause it to move in the opposite direction when it has reached either end of its travel in one direction, and to hunt for the calling line during its movement in either direction.

A further feature of the present invention is the provision of incans to cause the line finder to ren'iain in its set position upon the release of other apparatus concerned in the establishment of a connection at the terInina-.

tion of a conversation. Such line.findcr is adapted thereupon to take up the search for a newly initiated call with other similar idle switches.

Another feature. of the invention is its application to trunlohunting switches, where, upon the failure of the ordinary selector to find an idlel|'ll|il .1'h(-connection is switched to a selector oml'iodying the present invention, which takes up the search and perseyercs therein until an idle trunk is found.

In the drawings, Figure 1 represents diagrammatically a telephone exchange system line finders.

employing a plurality of line-finder switches, of which only two are shown, and which embody the present invention.

Fig. 2 is a diagrammatic representation of a telephone system inwhich the present invention is applied'to a trunk-hunting selector.

Referring now especially to Fig. 1, S represents a subscribers substation, LF and LF represent two line-finders of a group of several which serve the group of lines of which S is one. Line-finder LF is shown in such a condition that its next movement will be downward, while line-finder L]? is shown in the extreme downward position ready to move in an upward direction.

When the subscriber at substation S removes his receiver from its switchhook,. a circuit is established through the well-known line relay LR, which attracts its armatures and establishes a circuit to start several idle- This circuit extends from ground to outer armature and contact of relay LR, right-hand armature and contact of relay 1, sequence switch contact 3, transfer switch 5 and its upper. contact, winding of down-drive magnet 7 to grounded battery..- A parallel circuit is set up from ground, outer right-hand armature and contact of relay LR, right-hand armature and contact of relay 2, sequence-switch contact 4, transfer switch 6 and its lower contact, winding of up-drive magnet 10 to grounded battery.

Like parallel circuits for other idle line finders are set up, but not shown here. Line finder Ll", in the well-known manner, is caused to move downward, and line finder Ll in like manner is caused to move up ward.

We will assume that line finder Ll, whose brushes are B, B B and B.-a1e nearest to the terminals 11, 1'2, 13 and .14 of the calling line, is the first lo reach these terminals. A circuit is thereupon established from grounded battery, winding of relay 2, sequence-switch contact if), brush B, terminal l-l, resistance, 17. contact and inner armature LR to ground. Relay 2 attracts its armaturcs, thereby opening the circuit of up-drive magnet '10 and bringing the brushes of the line finder Ll? to rest upon the terminals of the calling-lino. A

s nond circuit is established from growl,

left-hand armatu-re and contact of rela 1 quence-switch power magnet 19 to grounded battery, causing the sequence switch to move under the control of its contact A into position 16. As this sequence switch moves out of position 1, and into position 14;, a circuit is set up from grounded battery, resistance 20, sequence-switch contact 21, brush B terminal 13, winding of cut-oil relay CO to ground. The consequent energization of relay CO opens the energizing circuit of line relay LR in the well-known manner, allowing relay LR to retract its armatures. The circuit for causing the movement of the rest of the line finders is now opened at the outer armature and contact of relay LR, and they come to rest in the position reached at that time.

When sequence switch 19 enters the second position and comes to rest in the sixteenth osition, talking conductors of the calling ine are connected to the repeating coil 0 at the sequence-switch contacts 22 and 23, brushes B, B and terminals 11 and 12, and the further progress of the call is taken care of in any well-known manner.

When a new call is initiated, line finder LF will be busy, and cannot be started in search of the calling line due to the open circuit found in sequence-switch contact 4. However, line finder LF, whose associated sequence-switch contact 3 is still close in position 1, will be available and, will start with other idle line finders on the search.

When, after one or more movements, line finder LF reaches its extreme downward position, projection 24', making physical contact with transfer switch 5, will act to transfer the power circuit for this line finder from the down-drive magnet 7 to the up-drive magnet 9. At the end of a full upward movement which may be accomplished in several searches, projection 25 will act in conjunction with transfer switch 5 to cause the further movement of this switch to, be in a downward direction.

At the conclusion of the conversation held over substation S and the connection established therewith, the actuation of the wellknown supervisory relay 26 will cause sequence switch 19 to move from its. sixteenth to its first or normal position, through a circuit extending from ground, armature and contact of relay'26, sequence switch cdntact 18 (position 16), winding of motor magnet of sequence switch 19 to battery and ground, whereline finder LF is again in condition to search fora calling line.

Referring now especially to Fig. 2, S represents a calling subscrlbers substatidn, S re resents a called subscribers substation, S and SS selector switches of ordinary construction, SS a selector switch em bodying the present invention and CS a connector switch.-

It will be assumed that the subscriber at brushes substation S removes his receiver from its hook, and that connection is established through the well-known cord finder and operators circuits indicated by the broken lines leading from substation S to the selector switch SS. Such indicated circuits are more fully described in patent granted to Lundell, 1,168,319. Upon ascertaining from the calling subscriber the number desired, the operator sets ister and presses a key K. A circuit is thereupon established from ground, throu h the key K, sequence-switch contact 101, t e winding of motor magnet 100 to grounded battery. Under the control of its contact A, the sequence switch moves from position 1 to position 6. In this position a circuit is established from grounded battery, left-hand winding of relay 30, sequenceswitch contact 102 to ground, thereby energizing relay 30, which in turn attracts its armatures. A circuit is now established from ground, left-hand armature and alternate contact of relay 30, sequence-switch contact 103, to the winding of motor magnet 100, and thence to grounded battery. This results in the movement of the sequence switch under control of its contact A into position 7.

In their normal position the brushes B B, B of'the selector switch SS rest on the lowermost set of contacts 31, 32 and 33.

Contact 33 is the test terminal of the trunks leading from this selector switch, and when it is busy will-be grounded in a manner to be described later. Brush B making contact with the terminal 33 of the lowermost set of such terminals will, it connected to a busy trunk, establish a circuit from ground, terminal 33, brush B, ri ht-hand armature and alternate contact 0 relay 30, ri hthand winding of relay 30 to grounded attery. Hence, when the sequence switch moves into position 7, relay 30 will be maintained in an energized position.

Under these conditions a circuit is now established from grounded battery, winding of magnet 35, sequence-switch contact 104,

alternate contact and left-hand armature of relay 30 to ground; The energization of magnet 35 causes the armatures of this magnet to be attracted, thereby bringing driving-rod 36 into frictional contact with the constantl rotating roller 37 to drive the 13 and B in an upward direc tion. Another circuit is at the same time established from ground, left-hand armature and alternate contact of relay 30, sequence-switch contact 105, brush 38 to the commutator segment 39, and thence through sequence-switch contact 106 to the left-hand winding of magnet 30, and ground.

Suppose, now, in its upward movement, brush strikes a contact 33 of an idle trunk, the energizing circuit for this relay 30,

' broken. Brush 38 will strike the insulating segment 30 when the brushes B B and B7 are accurately centered on the terminals 31, 32 and 33.

The deenergization of relay 30 results in the retraction of its armatures, whereupon .the energizing circuit for magnet 35 is broken at the alternate contact and lefthand armature of relay 30. At the same time'a circuit is established from ground, left-hand armature and normal contact of relay 30, sequence-switch contact 107, winding of the sequence-switch magnet 100 to grounded battery, thereby'driving the sequence switch under control of its contact A into position 16.

It should be noted at this point, that if the first set of contacts 31, 32 and 33, on which the brushes B B and B rested had been connected to an idle trunk, then the movement of the sequence switch into position 7 would have broken the energizing circuit of relay 30 at sequence-switch contact 102. Relay 30 would have retracted its armatures before magnet had become energized,'and no elevation of the brush carriage 41 would have taken place. Moreover, the sequence switch would have continued its movement under control of the circuits previously described into position 16.

We will assume that'an idle trunk has been found in the conductors T. Therefore,

- circuit for thesubscriber at substation S is extended from his substation, through the operators circuits indicated by the broken lines, through the sequence switch contacts 108, 109, through the brushes B and B, theterminals 31 and 32 of the trunk T to the connector switch CS, where this switch will be directed in a well known manner to the terminals of the called subscribers substation S.

Upon completion of the conversation, wellknown'supervisory signals indicate this fact to the operator, who thereupon depresses a key K. This completes a circuit from ground, key K, sequence-switch contact 110,

, winding 0 the sequence switch magnet 100 to grounded battery, thereby driving the sequence switch under control of its contact A intothe eighteenth position. In this position a circuit is completed from ground, sehence switch contact 111, through the winding of magnet 42 to grounded battery. Magnet 42 attracts its armature, thereby bringing the driving rod 36 into frictional en agement with the constantly rotating rol er 43, to restore the brushes B, B and such a normal position has been reached, circuit is established from ground, sequenceswitch contact-112, brush 38, commutator segment 44, sequence-switch contact 113, winding of motor magnet 100 to grounded battery. Sequence switch 100 is moved under control of its contact A into its normal position 1.

It should be noted at this point that when the brushes B B and B have seized an idle trunk, this trunk is thereafter made busy through a circuit which extends from ground, sequence-switch contact 114, normal contact and right-hand armature of relay 30, brush B, to the test terminal 33 of the trunk T.

Now let us assume that in their. upward travel the brushes B, B and B failed in their normal movement to seize an idle trunk. For this purpose special trunks at the top of the bank of contacts 31, 32 and 33 are connected to a few special selector switches such as SS It will be understood, therefore, that. these special selector switches are seized only when all of the trunks located in the panel of the selector switch SS are busy. The seizure of trunk T, providing it is idle, is followed by the establishment of a circuit from grounded battery, Y

winding of the relay 45, terminal-33 of the special set, brush B right-hand armature and normal contact of relay 30, sequence- 202, left-hand winding of relay 46 to grounded battery, whereupon a circuit is set up from ground, left-hand armature and alternate contact of relay 46, sequenceswitch contact 203, winding of sequenceswitch magnet 200 to grounded battery. Sequence switch 200 is energized through this circuit, and under control of its contact A moves into position 4. y

In this fourth position, a circuit is established from ground, left-hand armature and alternate contact of relay 46, sequenceswitch contact 204, right-hand armature and normal contact of relay 47, winding of magnet 48 to grounded battery. Magnet 48 at tracts its armature and brings thedrivin rod 49 into frictional engagement with the constantly rotating roller 50, tht! soy causing the brush carriage 51 of, the selector switch SS to be elevated. The brushes B,

B and B travel over the bank ofcontacts Q52, 53 and 54 hunting for an idle trunk. B,and 38 to their normal position. When The trunks appearing in this terminal mutator segment 57, sequence-switch contact 205, contact and left-hand armature of relay 58, winding of relay 47 to grounded battery. Relay 47 attracts its armatures and transfers the energizing circuit of magnet 48 to magnet 59. This circuit may now be traced from ground, left-hand armature and alternate contact of relay 46, sequence-switch contact 204, right-hand armature and alternate contact of relay 47, winding of magnet 59 to grounded battery. 'Magnet 59 attracts its armature and brings the driving rod 49 commutator segment 61, windin into frictional engagement with the roller 60, constantly rotating in the direction opposite to that of roller 50, whereby the brush carriage 51 is caused to move in adownward direction. 1

When relay 47 attracts its armatures, it establishes a locking circuit from ground, its left-hand armature and contact, to the contact andright-hand armature of relay 58, the winding of relay 47 to grounded battery. Thus, after brush 55' leaves commutator segment 57, as the brush carriage 51 moves in a downward direction, the relay 47 is maintained in its energized position.

As soon, however, as the brush carriage 51 reaches its extreme downward position, a circuit is established from ground,'brush 55, of the magnet 58 to grounded battery. agnet 58, upon attracting its armature, opens the locking circuit of relay 47 previously traced, at

a the contact and left-hand armature of test relay 58 The energizing circuit of. magnet 59 is now transferred by the right-hand armature of relay 47 back again to magnet 48,

and the brush carriage 51 is again elevated.

Suppose that by this time the trunk to connector switch CS has become idle, so that when brush B in its upward movement strikes terminal 54 of this trunk, the usual ground will not be found. The circuit, which may be traced from grounded battery, right-hand winding of relay 46, alternate contact and right-hand armature of relay 46,'brush B to ground through terminal 54 of the busy trunks, is now broken, as just stated. When the brush 62, by its position on an insulated portion of the commutator segment 63 breaks the circuit from ground, left-hand armature and alternate contact of relay 46, sequence-switch contact 212, brush 62, commutator segment 63, sequence-switch contact 213, left-hand winding of relay 46 to rounded battery, and the brushes B", B an B", are accurately centered on the terminals of the selected trunk, relay 46 will be deenergized. A circuit is now established from ground, left-hand armature and' normal contact of relay 46, sequence-switch contact 206, winding of the sequence-switch magnet 200 to grounded battery. Sequence switch200 moves under control of its contact A into the fifteenth position.

As the sequence switch moves out of its fourth position, the energizing circuit for either relay 48 or 59 is broken at the sequence-switch contact 204, and the brush carriage 51 remains in the position selected, at this time until the final release of this switch. In his position (15), sequenceswitch contac s 207 and 208 are closed, thereby extending the subscribers circuit through to the connector switch CS.

l'mlmthe control of the apparatus at the operatofs position, connector switch CS is caused to select the terminals of the called subscriber's substation S in a well-known At the termination of the conversation, the usual supervisory signals indicate, as before, to the operator the condition of the call on that particular circuit. In destroylpg'l'l'w connection the operator presses the keyK, whereupon the circuit previously described for stepping the switch SS into its normal position is established. When the brush B of switch SS moves from the terminal 33 of the trunk T, the energizing circuit for relay 45 is broken. Relay 45 deenergizes and upon the release of its armature, a circuit is established from ground, armature and normal contact of relay 45, sequence-switch contact 209, windin of sequence-switch ma et 200 to grounde bat- ,tery. Sequence switch 200 moves under the battery. Magnet 59 causes the return of brush carriage 51 to its extreme downward or normal position. When this position is reached, energizing circuit for relay 58-, heretofore described, is established. Relay 58 attracts its armatures, breaking the circuit of down-drive magnet 59, at itsnormal contact and right-hand armature, and establishing at its right-hand armature and alternate contact, a circuit from ground to the sequence-switch contact 211 winding of sequence-switch magnet 200. to grounded.

battery. Sequenceswitch 200 moves under control of its contact A? into the first 61' nor- 'mal position, whereupon energizingcircuit for relay 58 is broken and selector switch SS is left; in its normal condition.

W hat is claimed is:

1. In a telephone system, telephone lines, an 'ZllltOll'ltttlC switch in which said lines terminate in fixed terminals, means for causing said automatic switch to hunt over an entire row of said fixed terminals in a continuous rectilinear reciprocating motion, and means for causing said automatic switch to seize a set of electrically distinguished tern'iii'ials.

In a telephone system, telephone lines, an automatic switchin which said lines terminate in fixed terminals. means for causing said automaticswitch to hunt over an entire row of said fixed terminals in a continuous rectilinearireciprocating motion, and means for causing said automatic switch to seize an i ing. line, a plurality of panel type line finders, a circuit controlled by said line to control the actuation of all idle'line finders fassociated with said line, a'switch to con- ,trol the direction of movement of each line ffinder, said switch being actuated by said line finder at either end of its travel to cause.

idle set of terminals.-

3. In a telephone system, telephone lines,

an automatic switch in which said lines terminate in fixed terminals, means for causing said automatic switchv to hunt over an entire row of said fixed terminals in a con tinuous rectilinear reciprocating motion,

and means for causing said automatic switch to seize a calling line, said calling line-being connected to one set'of said terminals.

4. In an automatic switch, rows of circuit terminals, brushes arranged to travel over and make contact with saidterminals, means -for causing said brushes to travel over an entire row of said terminals in a continuous rectilinear reciprocating motion, and means for causing said brushes to seize a set of electrically distinguished terminals.

5. In an automatic switch, rows of circuit terminals, brushes arranged to travel over and make contact with said terminals, means for imparting to said brushes a continuous rectilinear reciprocating motion over the entire length of said rows of circuit terminals, and means for causing said brushes to seize a set of terminals in a predetermined electrical condition.

6. In an automatic switch, rectilinear rows of fixed terminals, movable brushes arranged to travel over and make contact with said terminals, means for imparting a reciprocating motion over the entire length of. said rows of circuit terminals to said brushes, and means effective during both the forward and return movement of said ment of all idle finders associated with said line, and a switch controlling the direction of movement of and controlled by-the movement of said line finders. i

8. In a telephone exchange system, a calling line, a plurality of panel type line finders, a circuit controlled by said line to control the actuation of all idle line finders associated with said line, a switch controlling the direction'of movement of and controlled 1) said line finders, and means for ar esting a moving line .finders upon the seizure of the calling line by any one of said line finders.

9. In a telephone exchange system, a callsaid line finder to travel in opposite direction, a switch to open said circuit to arrest the movement of said line finder, a circuit controlling said last mentioned switch including a brush of said line finder, and a gterininal associated with said line, and means for removing the successful line finder from the control of said first mentioned circuit.

10. In a telcphoncsystcm, a non-numerical switch, a'plurality of telephone lines terminating in said switch, a set of wipers arranged in operative relation to said lines, a source of power for moving said wipers, means for applying said source of power to move said wipers in one direction, means for disconnecting said source of power from said wipers, means for applying said source of power to move said wipers in an opposite direction, and means for causing said wipers to seize an electrically distinguished one of said telephone lines while moving in either direction.

In witness whereof, I hereunto subscribe my name this 19th day of September, ,D.

1916. ALBEN E. LUNDELI J. 

